C1-C3 Firewall Grommet Tarry Sealant

[Bob B.]

Hi all,

My 1960 had all the grommets, as well as the back of the master cylinder sealed with a black tarry sealant that ran down from the grommets. I just saw the same thing on a 1979 the other day, and I was wondering just what this material is and if it can be obtained anywhere.

Thanks,

Bob

[Terry M.]

Re: C1-C3 Firewall Grommet Tarry Sealant

I don't know what it is, but a look at some of the applicable AIMs should give one a GM part number which likely will not help one get it.
A suitable substitute might be some roof sealer from your local hardware or home supply store.

[Dick W.]

Re: C1-C3 Firewall Grommet Tarry Sealant

We have used plastic roof patch, as a substitute, with good results. Just takes time to apply correctly.

[Terry M.]

Re: C1-C3 Firewall Grommet Tarry Sealant

I have some gray 3M seam sealant that would work well if it were available in black. A quick search of 3M's web site is fruitless. Anyone know if they have it in black?

[Donald M.]

Re: C1-C3 Firewall Grommet Tarry Sealant

3M Super Weatherstrip adhesive (black) works for me.

[Dick W.]

Re: C1-C3 Firewall Grommet Tarry Sealant

Terry, at one time, it was available in black. I have about 1/2 box of black left. The part # is no longer valid in 3M's catalog along with the brushable weatherstrip adhesive.

[Chuck S.]

Re: C1-C3 Firewall Grommet Tarry Sealant

The next time you're in Phoenix, Albuquerque, or El Paso, pick up a quart of evaporative cooler sealant at Home Depot. It's an asphaltic based liquid that you can brush on or pour/dribble on (the authentic method of application for grommet sealing), and dries to a hard slick surface. It's the closest thing I've seen to the stuff on my 70.

Getting roofing cement or black weatherstrip adhesive to look authentic will truly be alchemy in my opinion, and will separate the restorists from the wannabees.